Centrifugal jet propulsion pump



June 20, i967 H. DAVIS 3,326,163

CENTRIFUGAL JETA PROPULSION PUMP Filed Feb. 8, 1965 5 Sheets-Sheet l -"1I l2 H @L l lll/111111111111111111111111!! HUNT DAVIS I N VEN TOR.

BY M. @um

.Emme 20, 19S? H. DAVIS 3,326,l63

CENTRIFUGAL JET PRoPuLsloN PUMP Filed Feb. e, 1965 s sheets-shew 2 FIGSFCT.7

HUNT DAVIS INVENTOR June 20, 1967 H. DAvls 3,326,163

CENTRIFUGAL JET PROPULSION PUMP Filed Feb. 8, 1965 5 Sheets-Sheet 5 HUNTDAVIS,

I N VEN TOR.

United States Patent C 3,326,163 CENTRIFUGAL JET PROPULSION PUMP HuntDavis, Williamsville, N.Y., assigner to Worthington Corporation,Harrison, NJ., a corporation of Delaware Filed Feb. 8, 1965, Ser. No.431,109 3 Claims. (Cl. 114-665) This invention relates generally tomulti-stage, centrifugal, jet propulsion systems, and particularly, topumps accommodated in a hydrofoil strut below the water level.

It is an object of the invention to provide a jet propulsion device forvessels whose eflciency is improved by reason of freedom fromcavitation, and is dimensioned for inclusion in a hydrofoil strut.

It is another object of the invention to provide deeply submerged inletsfor jet propulsion pumps which will avoid cavitation.

Yet another object of the invention is to provide a jet propulsionsystem with an engine that does not require speed-reduction gearsbetween the prime mover and propulsion pumps.

A further object of the invention is to provide multiple stage oflightweight pumps, rather than a simple heavy pump that would outweighthe multiple stage pumps.

Another object of the invention is to use a hydrofoil strut for ahousing for multi-stage pumps, so that an optimum eihciency, lowfriction strut form can be used, rather than the high friction, bulkystrut which is necessary if a large single-stage pump is used.

Still a further object is to dispose the jet propulsion inlet opening,pump and discharge jet opening coaxially, below the water surface, toachieve minimum power loss resulting from flow through duets.

These objects and advantages, as well as other objects and advantagesmay be attained by the device shown by way of illustration of theinventive concept, in the drawings in which:

FIGURE l is a top, schematic view showing the location of the gasturbine and power turbine in a typical ve-ssel;

FIGURE 2 is a front elevational View of the vessel, and underwaterstructure;

FIGURE 3 is a rear elevational view of the vessel and underwaterstructure;

FIGURE 4 is a side elevational view of the vessel and underwaterstructure;

FIGURE 5 is a vertical sectional view of a housing or `strut including amulti-stage, jet-propulsion pump;

FIGURE l6 is a top schematic view of the multi-stage -pump in thehousing;

FIGURE 7 is a partial, vertical, elevational view of the leading edge ofthe strut;

FIGURE 8 is a partial, vertical, elevational view of the trailing edgeof the strut; and

FIGURE 9 is a perspective View of the multi-stage pump, connected to theintake and discharge outlet in the housing.

The propulsion of hydrofoil vessels by water-jets is not ecient if asingle, large pump is used in an underwater strut; if the pump isinstead located in the vessel, the circuitous course traversed by thewater entails large power losses and the net positive suction head isseriously reduced. If the single, large pump is located in a strut orhydrofoil, the structure necessary to house the pump is so large as toentail excessive external drag. A construction in which many small pumpsare connected in parallel, has been found to be capable of inclusion ina strut having a streamlined cross-section. Operating at high speed,with the pump shaft vertical, permits the use of intake and dischargeports for the pump far below the water line, with generally linear pathsof intake and discharge -disposed in the same horizontal plane. Smallpumps in parallel permit great weight reduction. For servicing andrepair, the pump assembly may be conveniently removed in a verticaldirection.

Referring now to the drawings in detail, a typical hydrofoil vessel 11,may be propelled by gas turbines 12, driving' power turbines 13. Aforward strut 14 connected to the hull mounts a forward hydrofoil 15.Immediately below the gas turbines 13, rear struts 16 are attached tothe hull. These struts jointly support a rear hydrofoil 17. Drive shafts18, from the power turbines 13, pass through the hull downwardly throughthe rear struts 16. A stack of light weight, double-suction pumps 19 arelocated in each of the housings arranged in parallel to the driven bythe shaft 18'. The struts 14, 16, 16 have a generally streamlinecross-section. The upper pump is provided with a mounting ange 26 forattachment to the hull.

The leading edge of the struts 16, has a plurality of suction openings21. These openings 21 extend inwardly through suction-passages 31 in thestruts 16 and terminate in a flange 10 for attachment to pump suctioninlets 32. The pump suction inlets have anges 23 corresponding to theflanges 10, to which they may be detachably connected by bolts 24, or insome other suitable manner.

The trailing edge of the struts 16, has a plurality of discharge jetopenings 25. These openings 25 extend inwardly through jet dischargepassages 30v in the struts 16, and terminate in a flange 22, forattachment to the pump discharge outlets 26. The pump discharge outlets26 have flanges 27 corresponding to the flanges 22, to which they may bedetachably connected by bolts 24, or in some other suitable manner.

The suction openings 21 and the discharge jet openings 25 are locatedpreferably near the bottom of the struts 16, 16, so that when the vessel11 rises on its hydrofoils 15, 17, as shown in FIGURES 2, 3 and 4, thesuction openings 21 will still be located well below the waterlineproviding maximum net positive suction head. The jet discharge openings25, are similarly located, so that jet discharge is entirely below thewater level during normal operation.

The suction openings 21 and the pump suction inlets 32, as well as thepump discharge outlets 26, and discharge jet openings 25 are preferablyarranged so as to be as nearly in approximately the same horizontalplane as well as the same vertical plane as possible to obtain astraight, short flow path, to avoid power losse-s that arise in priorconstructions where the ilow is directed to and from the pump throughducts and pipes of greater length and complexity.

The flanges 22, 27, 10, 23 taper in a downward direction, as is shown inFIGURE 5. Thus, the pump assembly is removable vertically from thestruts 16 for ease of installation, servicing and repair of the pumps.

The stack of small pumps in parallel, effectively reduces weight of thepropulsion apparatus, eliminates the need for reduction gears andoperates with a high degree of eficiency.

The foregoing description is merely intended to illustrate an embodimentof the invention. The component parts have been shown and described.They each may have substitutes which may perform a substantially similarfunction; such substitutes may be known as proper substitutes for thesaid components and may have actually been known or invented before thepresent invention; these substitutes are contemplated as being withinthe scope of the appended claims, although they are not specificallycatalogued herein.

What is claimed:

1. In a 4marine craft having a buoyant hull and hydrofoils forsupporting the hull above the surface of the water at operationalspeeds, the pump propulsion system comprising:

(a) a generally vertical strut having a streamlined cross-sectionalconguration;

(b) a plurality of suction openings in the leading edge of the strut;

(c) a suction passage communicating with each suction opening;

(d) a plurality of discharge jet openings in the trailing edge of thestrut;

(e) a discharge jet passage communicating with each discharge jetopening;

(f) a plurality of superposed pumps in the strut;

(g) a suction inlet of each pump connected to each suction passage;

(h) a discharge jet outlet of each pump connected to each discharge jetpassage;

(i) the suction passages and the suction inlets each having opposinginterconnected edges on their end portions lying in the same plane;

(j) the discharge jet passages and the discharge jet outlets each havingopposing interconnecte-d edges on their end portions lying in the sameplane.

2. The combination claimed in claim 1 wherein the plane in which theopposing interconnected edges of the suction passages and the suctionVinlets lie and the plane in which the opposing interconnected edges ofthe discharge jet passage and the discharge jet outlets lie divergeupwardly from each other.

5 3. The combination claimed in claim 1 wherein:

(a) the opposing interconnected edges of the suction passages andsuction inlets are hanged and in registration with each other; and

(b) the interconnected edges on the end portions of discharge jetpassages and discharge jet outlets are anged and in registration witheach other.

References Cited UNITED STATES PATENTS 15 2,702,516 2/1955 Tinker 11S-163,006,307 10/1961 Johnson 114-665 3,143,097 8/1964 Meyerhoff 114-6653,143,972 8/1964 Smith etal 115-16 FOREIGN PATENTS 286,776 8/1915Germany.

MILTON BUCHLER, Primary Examiner.

25 ANDREW H. FARRELL, Examiner.

1. IN A MARINE CRAFT HAVING A BUOYANT HULL AND HYDROFOILS FOR SUPPORTINGTHE HULL ABOVE THE SURFACE OF THE WATER AT OPERATIONAL SPEEDS, THE PUMPPROPULSION SYSTEM COMPRISING: (A) A GENERALLY VERTICAL STRUT HAVING ASTREAMLINED CROSS-SECTIONAL CONFIGURATION; (B) A PLURALITY OF SUCTIONOPENINGS IN THE LEADING EDGE OF THE STRUT; (C) A SUCTION PASSAGECOMMUNICATING WITH EACH SUCTION OPENING; (D) A PLURALITY OF DISCHARGEJET OPENINGS IN THE TRAILING EDGE OF THE STRUT; (E) A DISCHARGE JETPASSAGE COMMUNICATING WITH EACH DISCHARGE JET OPENING; (F) A PLURALITYOF SUPERPOSED PUMPS IN THE STRUT; (G) A SUCTION INLET OF EACH PUMPCONNECTED TO EACH SUCTION PASSAGE; (H) A DISCHARGE JET OUTLET OF EACHPUMP CONNECTED TO EACH DISCHARGE JET PASSAGE; (I) THE SUCTION PASSAGESAND THE SUCTION INLETS EACH HAVING OPPOSING INTERCONNECTED EDGES ONTHEIR END PORTIONS LYING IN THE SAME PLANE; (J) THE DISCHARGE JETPASSAGES AND THE DISCHARGE JET OUTLETS EACH HAVING OPPOSINGINTERCONNECTED EDGES ON THEIR END PORTIONS LYING IN THE SAME PLANE.